KR100607218B1 - Method and apparatus for manufacturing metallic parts by injection molding from the semi-solid state - Google Patents

Abstract

The injection molding system includes a feeder 23 into which the metal is melted, and a first chamber 30 into which a predetermined amount of molten metal is injected. The piston 46 in the second chamber 50 first retracts to generate a suction force, allowing molten metal to enter the second chamber from the first chamber and evacuating the gas. The oil press 32 then pushes some of the molten metal remaining in the first chamber into the second chamber and discharges the gas present in the second chamber. The piston then injects molten metal from the second chamber into the mold 14. The molten metal is held in a semi-solid state before being injected into the mold.

Description

Method and apparatus for manufacturing metallic parts by injection molding from the semi-solid state}

This application is related to Application No. 09 / 160,330, entitled “Method and Apparatus for Manufacturing Metal Parts by Fine Die Casting”.

The present invention relates to a method and apparatus for manufacturing a metal part, and more particularly, to a method and apparatus for manufacturing a metal part by a process involving the injection of molten metal into a mold in a thixotropic state. .

One conventional method used to produce molded metal parts from molten metal is by die casting. The die casting method uses a liquid metal during casting, and as a result, the molded metal part produced by this method can have a low density. Low density molded metal parts are generally undesirable due to reduced mechanical strength, high porosity and increased microshrinkage. Therefore, it is difficult not only to accurately dimension a conventional molded metal part, but also to maintain its shape once dimensioned. Moreover, molded metal parts drawn by conventional die casting have difficulty in reducing the elastic stress induced therein.

In general, the thixotropic method for manufacturing molded metal parts is an improvement of the die casting method by injection molding a metal from a thixotropic state (semi-solid) rather than a liquid phase. The resulting molded metal part has a greater density than that produced by the die casting method. Thixotropic methods are disclosed in US Pat. Nos. 3,902,544 and 3,936,298, both of which are incorporated herein by reference.

Methods and apparatuses for manufacturing molded metal parts from molten metal in thixotropic states are also disclosed in US Pat. Nos. 5,501,226 and 5-285626 and 5-285627, which are also included in the prior art of this application. Methods for changing metals to thixotropic states by controlled heating and shear deformation in mold extruders are disclosed in US Pat. Nos. 5,501,226, 4,694,881 and 4,694,882. The systems disclosed in this patent document are essentially in-line systems in which the metal alloy is converted into a thixotropic state by means of a mold extruder and its pressing for the purpose of injection molding. All these steps are performed in one cylindrical housing. Within a single cylindrical housing, it is difficult to accurately control all process parameters, especially temperature, injection volume, pressure and time, resulting in molded metal parts with inconsistent properties.

Moreover, some of these systems require that the metal supplied to the feeder be in pellet form. As a result, if molded metal parts with undesirable properties are produced by such a system, it is impossible to recycle the defective parts unless the defective parts are first recast into pellet form.

Application No. 08 / 873,922, filed Jun. 12, 1997, which is a co-pending application of the present inventors, which is incorporated into the present application, discloses another improved method of manufacturing molded metal parts from molten metal in a thixotropic state Where the transformation from molten metal to thixotropic state occurs under different conditions at a location physically apart from the location at which the metal is injected into the mold.

There is a need for an improved system for manufacturing molded metal parts, i.e. a method for manufacturing molded metal parts that can work with molten metal in thixotropic conditions and accurately produce molded metal parts of specific dimensions within a small density tolerance. Furthermore, there is a need for a method of manufacturing molded metal parts that can consistently produce molded metal parts having desired characteristics and to easily recycle defective parts. Furthermore, there is a need for an improved method of manufacturing molded metal parts made of light metals such as magnesium.

It is an object of the present invention to provide a method and apparatus for manufacturing molded metal parts by injecting molten metal into a mold.

It is another object of the present invention to provide an improved injection molding system for manufacturing molded metal parts which can work with molten metal in thixotropic state and can produce molded metal parts with accurate dimensions within a small density tolerance. It is.

It is still another object of the present invention to provide an injection molding system for molded metal parts which can produce metal parts having desired characteristics in a consistent manner.

It is a further object of the present invention to provide an injection molding system which minimizes the amount of gas trapped in the molten metal prior to injection into the mold.

Another object of the present invention is to provide a molded metal part having a particularly smooth surface.

It is yet another object of the present invention to provide molded metal parts with reduced porosity compared to parts produced by known die casting and thixotropic methods.

It is a further object of the present invention to provide molded metal parts which do not require a separate additional process before being colored.

It is still another object of the present invention to provide an injection molding system for manufacturing molded metal parts that can easily recycle defective molded metal parts.

This series of objectives comprises the steps of introducing molten metal into a first chamber through a feed port, causing at least a portion of the molten metal to flow through the first chamber to an outlet, and at least a portion of the molten metal into a second chamber Drawing into the second chamber through the outlet by the suction force generated therein, pushing at least a portion of the molten metal remaining in the first chamber into the second chamber, and pushing the molten metal into the second chamber By an injection molding process from a mold into a mold.

The improved system includes a feeder in which the metal is melted. Molten metal flows from the feeder through the feed port to the first chamber. At least a portion of the molten metal is drawn into the second chamber through an outlet port in communication with the second chamber from the first chamber by a suction force. The hydraulic pressure of the first chamber pushes a portion of the remaining molten metal out of the first chamber through an outlet connected to the second chamber, whereby the molten metal and piston (commonly referred to as "plunger") in the second chamber are The gas accumulated in between is discharged. The pressure from the molten metal driven by the oil pressure to the second chamber causes the gas between the molten metal and the piston to flow through the piston and through the small space between the wall of the piston and the second chamber. The piston in the second chamber then injects molten metal that is substantially free of gas into the mold. Prior to injection, the piston in the second chamber generates suction to draw the molten metal from the first chamber while simultaneously adjusting the volume of molten metal contained in the second chamber prior to injection to exactly match the size of the mold part. To retreat.

The above-described methods and systems provide weight for the injection volume because the injection volume is determined by the position of the piston and forcibly releases gas which can be present in the molten metal by volume by 20% by the forward drive of the hydraulic machine before injection of the molten metal. Very precise control below ± 0.5%.

In addition, the method of the present invention can be used to mold thixotropic material parts that are more preferred than those molded by current thixotropic processes. They generally require less post-molding processing while obtaining more accurate molding volumes and smooth surfaces. This results in a stable production process over many manufacturing processes.

In addition, the method of the present invention can provide molded parts of extremely fine dimensions, such as components of 21.0 cm x 29.7 cm, rectangular shapes less than 1 mm thick (approximately the size of DIN standard A4 paper) and parts with more complex structures. have.

Additional objects and advantages of the invention will be described later. The objects and advantages of the invention may be achieved and attained by means and combinations particularly pointed out in the appended claims.

The invention is explained in detail with reference to the following figures.

1 is a schematic side view of an injection molding system according to an embodiment of the present invention.

FIG. 2A is a side view of one embodiment of a valve in an oil press, showing a positional state that prevents molten metal from flowing to the right point of the valve.

Figure 2b is a side view showing an embodiment of the valve in the hydraulic, showing a state that the molten metal can flow from the right side of the valve to the left side.

2C is a front view of one embodiment of a valve that is not coupled to an oil pressure.

Figure 2d is a side view showing one embodiment of a valve that is not coupled to the hydraulic.

3 is a side view showing another embodiment of the supply tank.

4A is a side view illustrating an embodiment of a nozzle block plate including a die plate that stops outflow with respect to the nozzle.

4B is a side view of another embodiment of a nozzle barrier plate including a recess for receiving a nozzle in a die assembly.

4C is a front view of another embodiment of a die assembly having a receiving slot for guiding a nozzle blocker.

4D is a side view of a barrier plate guide and drive assembly for a nozzle barrier plate.

5A is a plan view of an embodiment of a charging system for charging a metal ingot into the apparatus of the present invention.

5B is a side view of another embodiment of a charging system including a closed door.

5C is a side view of another embodiment of a charging system including a vacuum pump.

5D is a side view of an embodiment of a charging system including an inert gas screen.

5E-5H are plan views of another embodiment of a charging system for charging metal fluxes into the apparatus of the present invention.

5I is a perspective view of another embodiment of a charging system for charging metal fluxes into the apparatus of the present invention.

5J is a side view illustrating an elevator for transporting a metal ingot to a conveyor of a charging system.

6 is a side view of an embodiment of a feeder using a substantially vertical outlet containment rod.

7A is a schematic side view of an injection molding system including a support pin around a hydraulic press according to the present invention.

7B to 7G are cross-sectional views and perspective views illustrating the arrangement of the support pins.

8a to 8d are side views illustrating an embodiment of an injection chamber having a bipartisan piston.

9 is a side view showing the plug formation in the conventional injection nozzle.

10 is a side view showing an embodiment of an injection chamber including an outlet.

11A-11B are side views illustrating another method of piston operation.

12A-12B are side views of an embodiment of a canister including a two split hydraulic press.

Referring to the preferred embodiment of the present invention. The metal alloy is manufactured by injection molding by processing in a thixotropic state after melting a magnesium (Mg) alloy ingot or pellets. The invention is not limited to the manufacture of magnesium alloys and is equally applicable to other types of metals, alloys and materials.

As used herein, the terms "molten metal" and "melt material" encompass metals, metal alloys, and other suitable materials that can be converted into thixotropic states and processed in an injection molding system. A wide range of such metals is potentially useful in the present invention and include aluminum (Al), aluminum alloys, zinc (Zn), zinc alloys, and the like.

Unless stated otherwise, nouns mentioned herein include one or more meanings of plural.

Unless otherwise stated, the term "gas" refers to any gas (including air) that may be present in the injection chamber at the start of work and trapped in the injection chamber and discharged during operation of the system of the present invention.

Certain temperatures and temperature ranges cited in the detailed description of the present invention are applicable to preferred embodiments for processing Mg alloys in thixotropic conditions, but other metals and metal alloys in thixotropic states by those skilled in the art. Easily deformable in accordance with the teachings of the present invention to accommodate. For example, some Zn alloys become liquid at 450 ° C. or higher and thixotropic at 380 ° C.-420 ° C. The temperature of the injection molding system of the present invention can be adjusted to process the thixotropic Zn alloy.

1 shows an injection molding system 10 according to a first embodiment of the present invention. The system 10 includes a preheating tank 19 in which a piece of Mg alloy or ingot 18 is preheated to about 250 ° C. The conveyor belt 20 transfers the preheated Mg alloy pieces or ingots 18 to the holding tank 12. Other means of transport may be used. The metering device shown by the threaded screw 21 feeds the Mg alloy piece or ingot 18 to the feeder 23. The feeder 23 is provided with at least one heating element 25 located on its outer circumferential surface. The heating element 25 may be of any type conventionally and operates to maintain the feeder 23 at a high temperature sufficient to keep the metal alloy supplied through the feeder 23 in the liquid phase. For Mg alloy ingots this temperature will be approximately 600 ° C. or higher. Two level sensors 22 detect the minimum or maximum level of molten metal in the feeder 23. When the upper level sensor 22 detects that the molten metal has risen to the maximum point, it sends a signal to the microprocessor control unit (not shown), which instructs the screw 21 to stop administering. When the lower level sensor 22 detects that the level of molten metal has been exhausted to its minimum, the signal is sent to the control unit, which causes the screw 21 to operate so that more Mg alloy is supplied to the feeder 23. .

Preferably, sufficient metal should be maintained in the feeder 23 to supply about 20 times the volume required for one injection cycle (or injection). This is because the time required to melt the metal required for one injection cycle is longer than the injection cycle time, preferably the time is about 30 seconds.

The feeder 23 further comprises a lattice shaped filter 24 formed with holes small enough to prevent the Mg alloy piece 18 from passing through during melting. This is a major concern when the feeder 23 is first started up. Then, the alloy pieces will melt into the molten bath and melt without worry, even if large pieces are introduced later. A mixer (not shown) may be included in the feeder 23 for the purpose of uniformly distributing heat with respect to the metal supplied from the heating element 25 to the feeder 23.

The feeder 23, preheat tank 19 and all components there between comprise an inert gas atmosphere to minimize oxidation of the preheated and molten metal. Preferred is a mixed gas of carbon dioxide (CO ₂ ) and sulfur hexafluoride (SF ₆ ). However, other kinds of gases such as CO ₂ , SF ₆ , nitrogen or argon may also be used alone or in combination. Inert gas may be introduced into feeder 23 through port 11 (eg, from a pressure tank) to create an inert gas atmosphere at the top of the bath. In addition, the inert gas may be introduced into the preheating tank 19 around the screw to minimize oxidation. Therefore, it is preferable that the entire supply system described above is maintained in an inert gas atmosphere.

Molten metal is sequentially supplied into the barrel 30 which is temperature-controlled by gravity through a supply port 27 which may be selectively provided with a valve acting as a stopper (not shown). Preferably no valve is provided. The oil pressure machine 32 is disposed coaxially with the barrel 30 and extends along the central axis of the barrel 30. The outer diameter of the oil press 32 is smaller than the inner diameter of the barrel 30 so that molten metal may flow into the space between the oil press 32 and the barrel 30. In addition, the oil press 32 is controlled by the motor 33 to move forward and backward along the barrel 30 and the rotational movement about the shaft when it is necessary to stir the molten metal in the barrel 30. .

The valve 17 is mounted around the outer circumferential surface of the oil pressure machine 32 to divide the barrel 30 into an upper chamber and a lower chamber, respectively. The valve 17 selectively opens and closes the metal flow between the upper and lower chambers of the keg 30. Suitable valves having such a function are well known to those skilled in the art and can be used to meet the purposes of the present invention. Preferably, the valve 17 is mounted by friction on the inner circumferential surface of the barrel 30 and slidably mounted on the outer circumferential surface of the oil press 32, such that the oil press 32 is upwardly in the barrel 30. When retracting, the valve 17 moves relative to the oil pressure 32 to allow molten metal to flow therethrough, and also when the oil pressure 32 is advanced downward in the barrel 30, the valve 17 It moves relative to the oil press 32 to block its flow.

FIG. 2A is a side view showing one embodiment of a valve on an oil press that is in a state of preventing molten metal from flowing upstream of the valve (right side of the valve). FIG. FIG. 2B is a side view showing one embodiment of a valve on an oil press in a state that allows molten metal to flow downstream of the valve (left side of the valve). FIG. 2C is a front view illustrating an embodiment of a valve that is not coupled to the oil pressure. Figure 2d is a side view showing one embodiment of a valve that is not coupled to the hydraulic.

In the closed position of FIG. 2A, the rear end 17b of the valve 17 is in contact with the body 32b of the oil pressure machine 32. In this position, blocking of the flow causes the hydraulic press 32 to push the metal in the lower chamber into the injection chamber 50 through the outlet 37 (see FIG. 1) without backflow to the upper chamber (as in FIG. 2A). Make it work. In the open position of FIG. 2B, the front end 17a of the valve 17 is in contact with the head 32a of the oil pressure machine 32. In this state, the front end 17a of the valve 17 has a gap formed between the threads and the flow through the valve 17 takes place through this gap, so that the metal can flow through the valve. As a result, the metal in the upper chamber flows and collects in the lower chamber when the valve 17 is in the open position.

As shown, the hydraulic press 32 has a pointed tip, but any shape may be employed, including a blunt or rounded tip. Preferably, the tip of the oil press 32, the outlet 37 to prevent the flow of molten metal between the barrel 30 and the injection chamber 50 when the oil press 32 is fully advanced into the barrel (30) It has a shape that can be closed. During injection, the oil pressure machine 32 is preferably fully advanced into the barrel 30 so that the outlet 37 is closed. However, since the molten metal, which occupies the lower chamber of the valve 17 and the barrel 30, also prevents the molten metal from leaving the second chamber during injection, the oil pressure machine 32 does not need to be fully advanced. After injection, the oil pressure machine 32 retracts (but rotation can continue if rotation is used to agitate the molten metal in the barrel 30) and the piston 45 housed in the injection chamber 50 Beginning to retreat (to the right of FIG. 1), the volume of the injection chamber 50 is expanded by the desired volume corresponding to the dimensions of the molded part being manufactured. When the volume of the injection chamber 50 reaches the desired injection volume, the piston 45 stops. The piston 45 may be retracted at the same time as the oil pressure 32 is retracted or after the oil pressure 45 is retracted to a desired point.

After the piston 15 stops, the oil pressure machine 32 is advanced downward, so that a part of the metal collected in the lower chamber of the barrel 30 is pushed into the injection chamber 50 through the outlet 37. The pressure of the metal entering the injection chamber 50 assists in discharging the gas accumulated between the molten metal in the injection chamber 50 and the piston 45. The oil press 32 advances along the barrel 30 until its end closes the outlet 37 and in this state to leave the outlet 37 closed until the injection is terminated and the next injection begins. It is preferred to remain at.

During each injection, some gas accumulates between the molten metal and the piston 45 as the molten metal enters the injection chamber 50. The volume of this gas may account for up to 20% of the volume of the injection chamber 50. Injection of such a molten metal / gas mixture into the mold may include defects arising from an uneven surface, pores (caused by gas bubbles trapped within the metal surface), or defects caused by the inconsistent volume of molten metal being injected. This can lead to molded parts with defects. It is desirable to remove as much gas as possible before injection. In the process of the invention, the evacuation of such gases is achieved mainly by two methods. First, the piston 45 and the injection chamber 50 can discharge the gas in the same way as a pharmaceutical syringe that sucks liquid from the liquid container. Specifically, when the piston 45 retracts, a suction force that draws molten metal from the barrel 30 into the injection chamber 50 occurs, which pushes the gas behind it. Secondly, the additional part of the molten metal that flows into the second chamber by the oil press 32 is such that the gas accumulated between the molten metal and the piston 45 surrounds a small space between the piston 45 and the wall of the second chamber. Exit (i.e. gas is expelled to the right of the piston 45 due to the pressure of the molten metal). Optionally, an O-ring seal member or other tool may be coupled to at least a portion around the piston 45 to allow gas to pass behind the piston 45 to release it out of the system and prevent its backflow. The injection nozzle 57 has a nozzle blocking plate 15, which is lowered to prevent the molten metal from escaping from the injection chamber 50 when the hydraulic press 32 pushes the metal into the injection chamber 50. When the injection chamber 50 is filled with metal and substantially all of the gas has been discharged, the nozzle barrier plate 15 is lifted up and the nozzle 57 is moved forward (to the left in FIG. 1) so that the die 14 Contact with the opening. In a preferred embodiment, the movement of the nozzle 57 is accomplished by mounting the entire apparatus on a slide and moving the entire apparatus towards the die 14 (to the left in FIG. 1).

At the same time, the piston 45 is pushed to the left relative to the injection chamber 50 to allow molten metal in the injection chamber 50 to enter the mold 13 through the die 14. After the pre-set dwell time, the die is opened in two halves to remove the formed metal parts, thus starting a new cycle.

The molten metal is formed by the nozzle blocking plate 15, the seal member 41 of the piston 45, and the molten metal continuously occupying the barrel 30 during operation while the molten metal is accommodated in the injection chamber 50. It is substantially sealed from the gas which can flow into the injection chamber 50 from the outside of the machine. Although gas is present in the injection chamber 50 before starting work, virtually all the gas in the injection chamber 50 is discharged by the primary injection operation. Therefore, there is virtually no gas in the molten metal injected from the injection chamber 50 into the mold 13. Preferably, the amount of gas present in the injection chamber 50 during injection is less than 20% of the volume of the second chamber, more preferably 1% or less. In addition, as shown in FIG. 1, heating elements 70f-70j are provided along the longitudinal direction of the injection chamber 50.

Thixotropic metals are those that can be in a semi-solid slurry prior to injection. The thixotropic metal contains solid metal particles or regions suspended in the liquid phase. The resulting molded metal part contains a major or secondary solid phase region. Specifically, the metal that is in the thixotropic state (i.e., semi-solid state) may be heated in the form of molten metal or to a temperature between the liquid and solid temperature of the metal (i.e., in a semi-solid state) as described below. Can be supplied. If the metal begins to move downward along the length of the barrel 30 in the liquid phase, the temperature gradient in the barrel 30 is ultimately selected such that a thixotropic slurry can form in the injection chamber 50. As the liquid metal moves downward along the length of the barrel 30 it gradually cools to form a slurry. Such a configuration is described in detail in application No. 08 / 873,922, which is co-pending by the applicant, which is to be incorporated into the content of the present application. If the metal is supplied into the barrel 30 in a semi-solid slurry state, then the temperature gradient in the barrel 30 is selected so that the slurry can be maintained. For example, the temperature in the barrel 30 may be maintained at a temperature between the liquid and solid phase temperatures of the alloy as a whole. Regardless of how the thixotropic slurry is produced, the slurry ultimately depends on the material in the injection chamber 50. Preferably, the internal temperature of the feeder 23 is high enough to keep the metal in the liquid phase. In the case of the AZ91 Mg alloy, the heating element such that the temperature in the feeder 23 is above 600 ° C, preferably around 640 ° C near the upper surface of the molten Mg alloy and about 660 ° C near the lower region of the feeder 23. It is preferable to control (25). The heating elements shown at 70 are preferably resistor heating elements.

The temperature in the barrel 30 should be maintained above the solidus temperature below the liquidus temperature of the metal. The temperature near the heating elements 70a and 70b is preferably maintained at about 600 ° C. for the AZ91 Mg alloy. The temperature near heating element 70c is maintained at about 580 ° C. The temperature near heating elements 70d and 70e is maintained at about 550 ° C. for AZ91 Mg alloy. This temperature promotes the downward flow of metal towards the outlet 37 and prevents the flow in the opposite direction.

Preferably, the temperature near the heating elements 70f, 70g, 70h, 70i in the injection chamber 50 is maintained at about 550-570 ° C. to maintain a semi-solid state for the AZ91 Mg alloy. This low temperature also helps to prevent metal from flowing past the seal member 41. The temperature near heating element 70j is preferably maintained at about 570-580 ° C. for AZ91 Mg alloy.

It is possible to mold AZ91 Mg alloys in thixotropic conditions using such temperatures at each of the above positions. Under these conditions, one cycle lasts about 30 seconds or more. Molded metal parts with very smooth surfaces and minimal pores can be produced, which makes it possible to color directly without further processing. The castings are also extremely accurate in dimension and consistency and can be made to a thickness of less than 1 mm when the part has approximately DIN size A4 paper size (21.0 cm x 29.7 cm). Preferably, the thickness range of the molded part produced in accordance with the invention is between 0.5 and 1 mm for parts having approximately DIN size A4 paper size. Known diecasting and thixotropic methods cannot achieve thicknesses less than 1.3 mm for parts with approximately DIN size A4 paper sizes.

3 shows another embodiment of the invention with a feeder 23 ′. Like the feeder 23 of FIG. 1, the feeder 23 ′ of FIG. 3 includes a metering screw 21 ′, a level indicator 22 ′ and a heating element 25 ′. However, the feeder 23 'of FIG. 3 has a bottom area with a bottom surface at a lower position than the feed opening 27'. This subregion traps sludge and other materials that are heavier than molten metal and prevents them from passing through the feed port 27 'so that pure molten metal enters the keg 30. Another opening (not shown) may be provided for periodically discharging the heavy materials from this lower region.

FIG. 4A shows another embodiment of the present invention having a nozzle barrier plate 15 'positioned spaced a predetermined distance from die 14'. In this embodiment, when the nozzle barrier plate 15 'is pulled up, the nozzle 57 is pushed to the left to enter a relatively deep recess which partially extends into the support walls 59 and 60. As shown in FIG. The die 14 ′ is then positioned in contact with the support walls 59, 60. The recess suitably aligns the opening communicating with the nozzle 57 'and the mold 13'. The nozzle blocking plate may be maintained at a temperature that minimizes solidification of the molten metal in the nozzle. This can be achieved by providing heating elements on or within the barrier plate. However, the barrier plate may also be left unheated.

4B shows a side view of another embodiment of the present invention with a nozzle barrier plate 15 ″ retracting and advancing through a slot just inside the right edge of die 14 ". In this embodiment, when the nozzle block 15 "is raised upwards, the nozzle 57" is pushed to the left to enter a relatively shallow recess that extends partially into the die 14 ". The unit properly aligns the openings in communication with the nozzle 57 "and the mold 13". Support walls 59 'and 60' help align the nozzles.

FIG. 4C shows a front view of another embodiment of the present invention with a nozzle block 15 " 'retracting and advancing through a slot in the die 14 "' surface. In this embodiment, when the nozzle barrier plate 15 "'is lifted up, the shallow recess shown by the large circle around the small circle showing the opening formed into the die 14"' is exposed. The shallow recesses allow nozzles (not shown) to properly align with the openings formed in the die 14 "'. In another embodiment, not shown, the shallow recesses, with the blocking plate moving within the recesses, It may also be located on the support walls 59 'and 60' which receive the nozzle 57.

Another embodiment of the present invention shown in FIG. 4D relates to the operation of the nozzle barrier plates 15, 15 ′, 15 ″, 15 ″ ′ shown in FIGS. 1 and 4A-4C. In this embodiment, the blocking plate 15 is moved up and down in the blocking plate guide 16 between the surface of the die 14 and the support walls 59 and 60. The blocking plate guide 16 may be a vertical space formed between the die surface and the support wall as shown in FIG. 1 or formed in the die as shown in FIGS. 4A-4C. In addition, the guide 16 may include a space in another direction, such as a horizontal direction. The blocking plate 15 is moved along the guide 16 by a cylinder motor, a hydraulic cylinder and / or a pneumatic cylinder 46. The cylinder motor 46 is vertically supported by the cylinder guide 47.

In another embodiment, the disclosed methods can be used to make and form thixotropic metals. With the slight modification of the process parameters, substantially the same process can be used.

In one embodiment, metal ingots may be loaded into the apparatus of the present invention instead of metal pellets or chips. There are several advantages to using ingots instead of the metal pellets or chips. First, ingots are cheaper than pellets or chips. Second, the pellets tend to agglomerate with each other on the surface of the liquid metal in the feeder to form clusters. This increases the time it takes to melt the pellets because only the pellets at the bottom of the cluster are in contact with the liquid metal. The pellets on top of the cluster only touch the solid pellets below them. On the other hand, heavy ingots sink to the bottom of the feeder. Thus, the entire ingot is surrounded by the liquid metal and therefore melts faster than the pellets. A charging system configured to charge an ingot can be used to charge the feeder without re-casting the shaped metal parts that have undesirable properties and are recycled into pellet form. Therefore, according to another aspect of the present embodiment, recycled parts may be used instead of the ingot.

5A shows a top view of another charging system for FIG. 1 for charging metal ingot 63 to feeder 23. The charging system shown has a third chamber 66 (hereinafter referred to as a holding chamber) in communication with the feeder 23. The ingot may comprise Mg, Zn, Al or alloys thereof or other materials or alloys thereof. The ingot 63 is transferred from the first conveyor belt 61 to the second conveyor belt 62. A push arm 64 controlled by a conventional motor 65 pushes the ingot 63 into the holding chamber 66. The pusharm is of sufficient size to completely cover the opening of the holding chamber. If desired, the pusharm can form a rigid gas seal with the opening of the holding chamber. The ingot 63 in the holding chamber 66 is placed on the lower inclined portion 67, and a motor-controlled piston 68 pushes the ingot 63 into the feeder 23. The holding chamber is preferably maintained in an inert gas atmosphere supplied from a gas outlet. The gas may be a mixture of argon, nitrogen or sulfur hexafluoride and carbon dioxide. Preferably, the gas pressure in the holding chamber 66 is maintained to be greater than 1 atm to prevent external air containing oxygen from entering the feeder 23. The gas pressure and / or the location of the ingot can be monitored by one or more sensors. The controlled gas atmosphere in the holding chamber 66 reduces the amount of air in the feeder, thereby reducing the risk of explosion.

FIG. 5B shows a side view of another charging system for FIGS. 1 and 5A for charging the metal ingot 63 to the feeder 23. The ingot 63 is conveyed to the holding chamber 86 inclined downward from the conveyor 81. Entry to the holding chamber is controlled by the first door 82. Discharge from the holding chamber is controlled by the second door 84. The chamber may be heated to 100-200 ° C. by the heater 85 to evaporate the moisture of the ingot surface. The holding chamber 86 operates as follows. First, the door 82 opens as the ingot 63 approaches. Preferably the door 82 is opened by lifting up and down or moving laterally along the wall of the chamber 86. When the ingot 63 enters the chamber 86, the first door 82 is closed. After the first door 82 is closed, the second door 84 is opened and the ingot 63 moves out of the chamber 86. The conveyor 81 can move continuously through the chamber 86 by moving in the open and closed state of the doors 82 and 84. As an alternative, the conveyor 81 moves intermittently. In other words, the conveyor stops when the ingot approaches the door 82 and when the ingot is inside the chamber 86. This allows the door to be sealed. In addition, the conveyor 81 may end at the inclined portion of the chamber 86 so that the ingot slides downward by gravity.

In another embodiment, not shown, the charging system shown in FIG. 5A is characterized in that the door 82 of FIG. 5B is located between the conveyor 62 and the chamber 66 and the door 84 is melted with the chamber area 67. It may be used located between the tanks (ie, melt feeder) (23). The door 82 opens in synchronization with the movement of the push arm 64 while the door 84 opens in synchronization with the movement of the piston 68.

The retaining chamber 86 of Figure 5b is coupled with a melting tank 23 ". The melting tank 23" includes one metal level detector 22 ". Alternatively, the two levels shown in Figure 1 are shown. Sensor 22 may be used. Tank 23 "also includes a gas opening 11". An inert gas, such as at least one gas selected from the group comprising nitrogen, argon, SF ₆ and CO ₂ , may be used. (Ie, under pressure from a pressurized tank) is introduced into a melt chamber 23 ". The pressure of the gas being pumped is preferably greater than 1 atmosphere to prevent air from entering the melting tank 23 "through the holding chamber 86 (pumped gas flows out through the chamber 86 and thus air Is prevented from entering the chamber 86).

Also, the melt chamber shown in FIG. 5B has a heater 25 ", a screen 24", and a supply port 27 "located above the bottom of the tank, similar to the supply tank 23 'shown in FIG. The screen may be formed in or on the feed opening 27 ″ as shown in FIG.

As an alternative, a vacuum pump 87 may be attached to the chamber 86 between the doors 82 and 84 as shown in FIG. 5C. When the ingot 63 is introduced into the chamber 86, the doors 82 and 84 are all closed and the vacuum pump makes the chamber 86 almost vacuum. The door 84 is then opened to release the ingot 63 into the melt tank 23 ". When the door 84 is opened, the chamber 86 is in a vacuum, so even a slight amount of air is melted into the melt tank 23". Don't go inside.

As shown in FIG. 5D, the inert gas screen 90 is discharged from the inert gas source 88 through an optional suction pipe or through hole 89 across the rear surface of the door 82 and / or 84. Can be made. The inert gas screen 90 prevents air from entering the chamber 86 and the tank 23 ". The inert gas comprises at least one gas selected from the group consisting of argon, nitrogen, CO ₂ and SF ₆ . The gas screen of FIG. 5D can be used with the vacuum pump of FIG. 5C to minimize air ingress into the melting tank 23 ". Air control means such as the melt tank gas opening 11 ", doors 82 and 84, vacuum pump 87 and inert gas screen 90 all allow air to flow into the melting tank and / or the holding chamber. Used to reduce the chance of explosion by preventing

5E and 5F show another example of the charging system for FIG. 5A. The holding chamber 66 'uses a movable through plate 72. As shown in FIG. 5e shows a plan view of the charging system with blocked entry to feeder 23. The movable through plate 72 includes a through hole 73 larger than the ingot. When the ingot should no longer be added to the feeder 23, the plate 72 is moved to one side by the movable arm 74 to cover the inlet of the feeder. As shown in FIG. 5F, when the ingot is to be added to the feeder 23, the plate 72 moves to the other side so that the through hole 73 coincides with the opening of the feeder 23. According to this method, the ingot conveyed from the conveyor 61 ′ passes through the through hole 73 and enters the feeder 23. In the embodiment shown in FIGS. 5E and 5F, the through plate 72 is used in place of the push arm 64 and the piston 68 shown in FIG. 5B. However, the through cover plate 72 may be used in addition to the push arm 64 and the piston 68. In this case, the plate 72 blocks the entry of the ingot sliding down the inclined surface 67.

5G and 5H show another charging system for FIGS. 5E and 5F. In this embodiment, the holding chamber 66 "uses a movable cover plate 75 instead of the movable through plate 72. The cover plate 75 is roughly large enough to cover the opening of the feeder 23. 5G shows a plan view of the charging system with closed entry to the feeder 23. The movable arm 74 'moves the cover plate 75 over the opening of the feeder 23 to convey the conveyor 61. As shown in FIG. Block ingress of the ingot supplied from As shown in FIG. 5H, when additional ingots are to be supplied to the feeder 23, the cover plate 75 moves to the other side or is raised (out of the plane of the drawing) to expose the opening for the feeder 23. Let's do it. The ingot fed from the conveyor 61 "can fall directly into the feeder 23. In the embodiment shown in Figures 5g and 5h the coverplate 75 is the pusharm 64 shown in Figure 5b. And piston 68. However, the cover plate 75 may be used in addition to the push arm 64 and the piston 68.

5I shows another charging system for FIG. 5A. The opening 78 of the feeder 23 is covered by a movable feed chamber 76 such as a cylinder. The cylinder 76 has a through hole 77. The through hole 77 is at the same level as the conveyor 81 ′ as shown in FIG. 5J. To further add ingot 63 to feeder 23, movable arm 74 ″ moves the cylinder to a position where aperture 77 aligns with the end of conveyor 81 ′ so that ingot is conveyor 81 ′. From the through hole (77) into the cylinder (76) and back through the opening (78) to the lower feeder (23). This cylinder 76 is moved in any direction (ie, left or right) so that the end of the conveyor is no longer aligned with the aperture 77. Although the transfer chamber 76 has been described as a cylinder, it may have any other shape, such as a cube. The transfer chamber can also be used with the push arm 64 and piston 68 shown in FIG. 5A. In this case the ingot 63 will slide down the slope 67 into the transfer chamber instead of falling directly into the feeder 23. The transfer chamber 76 may also be used with the holding chamber 86 of FIG. 5B. This is shown in Figure 5J.

5J shows elevator 100 delivering the ingot to conveyor 81 'in retaining chamber 86'. As shown in FIG. 5B, the holding chamber 86 may have one or two doors 82 and 84. In FIG. 5J only one door 82 ′ is shown for clarity. The ingot on the platform 101 is elevated upwards towards the holding chamber 86 '. Each platform includes a movable platform top plate 103 coupled by a platform base 102 and at least one connector 104. When each platform reaches the top of the conveyor 81 ′, the lifting member 105 raises the pawl 106 and pushes up the rear end of the platform top 103. The rear end of the platform top plate 103 is lifted above the platform base 102 by the lifting member 105, which causes the ingot 63 to slide from the platform top plate to the conveyor 81 '. The ingot 63 passes through the conveyor 81 'and into the feeder. Ingot 63 may optionally pass through transfer chamber 76 shown in FIGS. 5I and 5J. After the ingot is removed from the platform top, the lifting member lowers the pawl 106 to position the platform top 103 over the platform base 102. The lifting member 105 is then separated from the first platform 101 and the next platform 101 is raised to repeat the process.

The connector 104 may be a bolt that rotatably couples the platform top plate 103 and the base 102. Preferably, the platform top plate is rotated about 20 degrees by the lifting member 105. As an alternative, the entire platform 101, not just the platform top plate, can be lifted by the lifting member. In addition, the elevator 100 may be used with the holding chamber 66 shown in FIG. 5A and the ingot may slide into the feeder 23 by sliding down the inclined surface 67.

Preferably, the movement of the lifting member 105 is synchronized with the opening of the door. For example, when the lifting member 105 lifts the pawl 106, the door 82 'opens simultaneously to allow the ingot 63 to pass through the retaining chamber 86'. Furthermore, the cover plates 72 and 75 shown in FIGS. 5E-5H or the transfer chamber 76 shown in FIG. 5I may also be synchronized with the door 82 '. Thus, after the door 82 'is closed, the cover plate or transfer chamber may move to open the entry into the feeder 23. If a rear door 84 (shown in FIG. 5B) is also provided, it must be opened after the front door 82 'is closed. The elevator 100 can also be used with the conveyor 61 and the holding chamber 66 shown in FIG. 5A.

6 shows another embodiment of a feeder 23 using a substantially vertical outlet containment rod. In FIG. 1 (as well as FIG. 5B), the supply port 27 is blocked by a grid-shaped filter 24. The grating is necessary to prevent the unmelted piece of metal from escaping the feeder 23 from the feeder 23 through the feeder 27. However, the metal ingot 63 sinks to the bottom of the feed port and lies flat on the grid. This positioning is undesirable because the ingot substantially blocks the flow of liquid metal into the keg 30 through the feed port 27 ". To prevent the ingot from blocking the grating, see FIG. As shown, an outlet containment bar 76 must be used on the feed port 27 "'. The rod may be of any shape as long as it prevents the sunken ingot 63 from flattening across the feed opening 27 "'. For example, as shown in FIG. The rod at can project over the rod near the circumference of the feed port so that it can rest sideways towards the edge of the feeder 23 "'while the ingot 63 melts. The supply tank 23 "'may also have a lower region with a bottom surface at a lower position than the supply opening 27"' as shown in FIG. The ingot that sinks and contacts rod 76 will deviate laterally and bias towards the lower region. The ingot will melt in the lower region without blocking the supply port 27 "'.

FIG. 7A shows a side view of another embodiment of the present invention having support ribs or pins 34 disposed in the oil press 32. The figures are not drawn to scale and the thickness of the barrel 30 is rather exaggerated for clarity. The heater 70 is provided but omitted in the drawings for clarity. The pin 34 is preferably attached to the oil pressure machine 32 and rests on the inner circumferential surface of the barrel 30 to move coaxially along the longitudinal direction of the barrel 30 and / or to rotate about the axis 38 of the barrel. Can slide The movement allows the pin 34 to rotate the inner circumferential surface of the barrel 30. Alternatively, the pin 34 may be attached to the inner circumferential surface of the keg 30 so that the oil pressure 32 itself can slide. The pin 34 may be made of the same material as the hydraulic press 32 or other material that can withstand the required process temperature. The purpose of the pin is two aspects. The first purpose is to prevent the oil pressure 32 from tilting or shaking with respect to the shaft 38 of the barrel. The oil press 32 is quite long, so it is easy to tilt without the pin 34. The tip of an unsupported oil press is closer to the bottom than the top of the inner face of the barrel under its own weight. The pin 34 contacts the inner surface of the barrel 30 to prevent the oil pressure from tilting or shaking, thus centering the oil pressure 32 to align with the axis of the barrel. The second purpose is to improve the uniform temperature distribution of the molten metal.

As shown in FIG. 7A, the region 32c of the hydraulic oil moving inside the valve 17 is free of pins so as not to contact the valve. A cross sectional view along line A-A 'of FIG. 7A is shown in FIG. 7B. As can be seen, the pin 34 does not extend all over the outer circumferential surface of the oil press 32 so that the metal can flow through the barrel. The pins 34 may be arranged in a number of different forms around the hydraulics 32. For example, as shown in FIG. 7C, two pins may be disposed at periodic intervals 36 on opposite sides of the rod. Each gap may be formed of the same length or different lengths. For example, the pins may be spaced closer together at one end than at the other end of the oil press, and may also be disposed one or more closer near the center than at both ends of the oil press. As an alternative, as shown in FIG. 7D, two or more pins (ie three) may be arranged at predetermined intervals 39 around the oil pressure. Again, the longitudinal spacing 36 and the circumferential spacing 39 of the oil press may be the same or different. Furthermore, as shown in FIG. 7E, the pin 34 may be inclined at one or more angles rather than 90 degrees with respect to the axis of the keg. Otherwise, other pins may be angled rather than 90 degrees and only some pins 34 may be tilted 90 degrees. As mentioned above, two or more sloped pins may be provided spaced along the rod at equal or unequal spacing. Moreover, the width and / or thickness of the oil press in the longitudinal and / or circumferential direction of the pin may be different as shown in FIG. 7F. In addition, as shown in FIG. 7g, the pins may be staggered from each other in the longitudinal direction of the hydraulic press. In general, although the pin 34 is mounted inside the keg 30 rather than the oil press 32, one or more combinations of the above arrangements are possible. Along with the pin 34, the oil pressure machine 32 can also be used with the embodiments shown in FIGS.

8A-8D show side views of another embodiment of an injection chamber 50 '. In this embodiment the piston 45 'consists of two parts: the inner part 46 and the outer part 47. The outer side is a substantially hollow cylinder and the inner side is a cylinder coupled slidably into the outer side. The two parts have separate drive mechanisms. 8A shows a state in which the oil pressure machine 32 is retracted back in the keg 30 so that metal can flow into the injection chamber 50 '. The inner portion 46 of the piston extends sufficiently to close the outlet 58 to prevent metal from flowing from the injection nozzle 57 "'to the die 14" ". The outer portion 47 of the piston is an injection chamber. The retractor is retracted to expand the volume of 50 'to the desired volume. Likewise, the oil pressure machine 32 retracts in the canister 30. In this configuration, the metal is ejected from the canister 30' by the injection chamber 50 '. While it flows in, the injection nozzle hole 58 is closed by the piston inner portion 46 so that no metal flows into the die beforehand. A heating element 70 is provided but omitted in the drawings for clarity.

8B shows the next step of the injection chamber 50 'operation. Here, the oil pressure machine 32 fully advances into the cylinder 30 and sends the remaining metal from the cylinder 30 to the injection chamber 50 '. The piston inner portion 46 is still fully advanced to close the injection nozzle hole 58. The piston outer portion 47 is still retracted to allow metal to flow from the barrel 30 into the injection chamber 50 '. This configuration also prevents metal from flowing into the die in advance.

8C shows the next step of the injection chamber 50 'operation. The piston inner portion 46 is retracted into the piston outer portion 47. The injection nozzle is finally opened. However, there is no further metal flow from the barrel 30 to the injection chamber 50 'since the opening of the barrel is closed by the advanced oil pressure 32.                 

8d shows the final stage of operation of the injection chamber 50 '. Both the inner and outer portions 46 and 47 of the piston 45 'are pushed to the left to direct molten metal in the injection chamber 50' through the injection nozzle 57 "'into the die 14" ". As noted above, the injection nozzle 57 "'may move forward and contact the opening in the die prior to moving the piston 45' to the left.

After the step shown in FIG. 8D, the oil press 32 and the piston outer portion 47 retract, while the piston inner portion 46 is positioned to close the injection nozzle hole 58 as shown in FIG. 8A. The process is repeated.

Alternatively, the piston inner portion 46 may be partially retracted into the piston outer portion 47 (as shown by dashed lines in FIG. 8C) instead of fully retracting as shown in FIG. 8C to allow metal to flow into the opening of the die. . Moreover, instead of moving leftward by the piston outer portion 47 as shown by the solid line in FIG. 8D, the piston inner portion 46 is ejected from the piston 57 (as shown by the dotted line in FIG. 8D) than the injection nozzle 57 ″. The nozzle blocking plate can be replaced by the piston inner portion 46. Therefore, the nozzle blocking plate can be replaced by the piston inner portion 46. Therefore, the apparatus of Figs. 1 is improved because only one motor is needed to move the two parts of the piston instead of two (one driving the piston and the other blocking plate).

Furthermore, the apparatus shown in FIGS. 8A-8D prevents metal from accumulating in the nozzle hole and allows the piston inner portion 46 to allow molten metal in the injection nozzle 57 "'to enter the opening of the die. Without the two parts of the piston, in the conventional injection nozzle as shown in Fig. 9, molten metal may accumulate and solidify with the plug 91 even after the injection movement by the piston. Since it is in contact with a cold wall (or die support wall), the plug 91 is formed in the discharge hole 92 of the injection nozzle 90. Thus, the nozzle tip is at a lower temperature than other parts of the injection chamber. Such a plug is undesirable because it blocks the discharge from the injection nozzle to reduce the amount of metal injected into the mold or impede the operation of the device.

However, the inner part of the piston 46 in Figs. 8A to 8D closes the injection nozzle hole from the inside of the nozzle prior to the piston injection motion, thereby preventing any metal from accumulating in the hole. In addition, as shown in FIG. 8A, the piston inner portion may be designed to push out residual metal accumulated in the hole by including an inclined tip 49 of the piston inner portion 46 extending into the hole. have.

10 shows another embodiment of the present invention. In this embodiment, an auxiliary gas outlet 110 is added. The auxiliary gas outlet port allows the gas 111 trapped between the molten metal 115 and the piston 45 to escape from the injection chamber. In addition to the openings around the piston, the use of outlet 110 allows more gas to exit the injection chamber. As an alternative, the outlet 110 may comprise means by which only the entrapped gas can escape. The outlet 110 is preferably located between the inlet of the injection chamber and the point where the piston is retracted. The outlet may comprise any structure that allows gas trapped in the injection chamber to escape while air outside the device does not enter the injection chamber and molten metal does not escape through it during injection into the mold. . For example, the outlet 110 may include a semipermeable material such as porous ceramic 112. The porous material passes gas but not molten metal. The discharge port may be connected to a discharge pipe 113 having a one-way valve 114 to allow the discharge of gas and prevent external air from entering the injection chamber.

11A and 11B show another method of piston operation. While the nozzle blocker 15 blocks metal flow into the mold before the molten metal 115 is injected into the mold 14, the piston is partially advanced forward. The forward movement of the piston causes the trapped gas to exit the injection chamber. The gas exits through the space between the piston and the injection chamber wall and, if any, through the outlet 110. However, since the nozzle blocking plate is closing the nozzle, the molten metal does not flow into the mold due to the forward movement of the piston. Once the trapped gas is compressed and exits the injection chamber, the blocking plate is raised and the piston is advanced forward to eject molten metal into the mold as shown in FIG. 11B.

If two parts of the piston shown in Figs. 8A to 8D are used, a similar gas compression discharge method can be used. With the inner part of the two parts of the piston closing the injection nozzle, the outer part is partially advanced to discharge the trapped gas out of the injection chamber. Then, when the inner part of the piston retracts, the injection nozzle is opened and the piston moves forward to inject metal into the mold.                 

12A shows another embodiment of a keg in accordance with the present invention. In this embodiment, the hydraulic pressure is composed of two parts, the inner portion 32d and the outer portion 32e. The outer portion 32e is slidably mounted on the first portion 32d to move forward and backward along the axis of the barrel 30. The inner portion 32d has a substantially circular cross section, the entire outer portion 32e has a donut-shaped cross section, and its inner diameter is slightly larger than the diameter of the inner portion 32d. The two-part hydraulic operates on a principle similar to the two parts of the piston shown in FIGS. 8A-8D. After each injection cycle, the inner hydraulic part 32d is partially retracted while the outer hydraulic part 32e is fully retracted. When molten metal flows from the feeder 23 through the barrel 30 to the injection chamber 50, the inner portion 32d of the oil press extends downward in the longitudinal direction of the barrel so that the molten metal has a uniform temperature on its axis. Rotate about The outer portion 32e then moves forward to push the molten metal in the barrel into the injection chamber. Prior to the injection of metal from the injection chamber into the mold, the entry into the bin through the outlet 37 must be closed. This can be done by blocking the outlet 37 at the end of the inner side 32b of the oil press or by blocking the outlet 37 with two parts of the oil press. The shape of the outlet 37 may correspond to the tip of the combined hydraulic part so that the outlet 37 may be blocked when the two parts of the oil pressure are fully advanced, as shown in FIG. 12B. When the outer portion 32e is fully advanced it substantially blocks the inlet from the melt feeder 23 to the canister 30 so that the molten metal does not substantially enter the canister 30 when the outer hydraulic portion is fully advanced. Do not.

It is important to note that all embodiments shown in FIGS. 1-12 may be used together, separately, in combination or in a substituted manner without departing from the scope of the present invention. In other words, any one or more refinements shown in FIGS. 2-8 can be added to the basic device shown in FIG. 1 without departing from the scope of the present invention.

This application claims priority to US Provisional Application No. 60 / 080,078, filed March 31, 1998, which is incorporated by reference in its entirety.

While specific embodiments of the invention have been shown and described above, it is apparent that the invention can take various modifications and embodiments within the scope of the appended claims. For example, various metals can be processed in a thixotropic state by adjusting the temperature gradient using the method and apparatus of the present invention.

Claims (74)

Injecting a molten material into the first chamber; Passing the molten material through the first chamber to a second chamber; Maintaining the first chamber and the second chamber at a temperature between the liquidus temperature and the solidus temperature of the molten material to maintain the molten material in a semi-solid state in the second chamber; Pushing the molten material remaining in the first chamber into the second chamber; And And injecting the molten material from the second chamber into a mold. The method of claim 1, wherein in the step of allowing the molten material to pass through the first chamber to the second chamber, suction force is introduced into the second chamber to draw the molten material from the first chamber to the second chamber. Generating. 3. A method according to claim 2, wherein the suction force in the second chamber is generated before pushing a portion of the molten material from the first chamber to the second chamber. 3. The method of claim 2, wherein the piston in the second chamber retracts to generate a suction force that draws the molten material into the second chamber. 2. A method according to claim 1, wherein the hydraulic pressure in the first chamber is advanced to push a portion of the molten material from the first chamber to the second chamber. 6. The method of claim 5, wherein the first chamber comprises a valve to allow molten material to pass only in the direction towards the second chamber. 6. A method according to claim 5, characterized in that during the injection the hydraulic pressure is advanced so that the end of the hydraulic pressure closes the outlet of the first chamber to prevent molten metal from passing between the first and second chambers. . 6. The method of claim 5, comprising rotating the oil press to maintain a uniform temperature distribution of molten material in the first chamber, wherein the oil press includes support pins arranged around the oil press. . The method of claim 1 wherein the molten material is a metal. 10. The method of claim 9, wherein the molten material is a molten magnesium alloy. 10. The method of claim 9, wherein the liquid metal, which is the molten material, is injected into a mold, and the injected metal is solidified into a metal part in the mold. The method of claim 1, wherein the first chamber is positioned above the second chamber so that gravity acts to help the molten material pass from the first chamber to the second chamber. 13. The method of claim 12, wherein the molten material passing into the second chamber discharges gas present in the second chamber to the outside. The method of claim 1 wherein gas present in the second chamber is discharged out of the second chamber through a porous material that prevents passage of the molten metal. The method of claim 1, further comprising: before the step of introducing the molten material into the first chamber, the step of introducing a solid material into the feeder, and melting the solid material in the feeder, The molten material is introduced from the feeder into the first chamber. The method of claim 15 wherein the solid material is a metal ingot. The method of claim 16, Before the step of injecting the solid material into the feeder, further comprising the step of injecting the metal ingot into a third chamber in communication with the feeder, The metal ingot is conveyed from the third chamber into the feeder. 18. The method of claim 17, wherein the third chamber or the feeder contains an inert gas atmosphere. 19. The method of claim 18, wherein the inert gas comprises at least one gas selected from the group consisting of argon, nitrogen, SF ₆ and CO ₂ . 19. The method of claim 18, wherein the inert gas atmosphere is maintained by a door installed in the third chamber. 18. The method of claim 17, wherein the step of introducing the metal ingot into the third chamber and the step of transferring the metal ingot from the third chamber into the feeder, Opening a first door to the third chamber; Advancing the metal ingot into the third chamber; Closing the first door; Opening a second door; And Advancing the metal ingot from the third chamber to the feeder. 18. The method of claim 17, wherein in the transferring of the metal ingot from the third chamber into the feeder: The metal ingot is conveyed into the feeder along an inclined surface. 18. The method of claim 17, further comprising the step of controlling entry of said metal ingot from said third chamber to said feeder prior to transferring said metal ingot from said third chamber into said feeder. Way. 24. The method of claim 23, wherein controlling the entry to the feeder is performed by the movable cover plate having a passage hole. 16. The method of claim 15, comprising controlling the entry into the feeder by a movable transfer chamber prior to introducing the solid material into the feeder. 27. The method of claim 25, wherein controlling the entry to the feeder is performed by the movable transfer chamber comprising a cylinder having a through hole. The method of claim 1, wherein the step of injecting the molten material from the second chamber into a mold, Opening the injection nozzle in the second chamber; Advancing a piston to inject the molten material into the mold through the injection nozzle; And Closing the injection nozzle. 28. The method of claim 27, wherein closing the injection nozzle is performed by a nozzle barrier plate. 28. The second chamber of claim 27, wherein the piston surrounded by the seal member is partially advanced before the molten material is injected into the mold to compress the gas present in the second chamber to prevent passage of the molten material. Venting out. The method of claim 5, wherein the step of pushing the molten material remaining in the first chamber to the second chamber and the step of injecting the molten material from the second chamber into the mold, Advancing the hydraulic pressure in the first chamber, the hydraulic pressure closing the outlet of the first chamber during injection to prevent molten material from passing between the first and second chambers; Opening the injection nozzle in the second chamber; Injecting the molten material into the mold through the injection nozzle by advancing a piston; Retracting the oil pressure; And Retracting the outer portion of the piston to generate suction in the second chamber to draw the molten material from the first chamber to the second chamber with the inner portion of the piston fully advanced to close the injection nozzle. Characterized in that. delete A first chamber for holding the molten material; A hydraulic press for moving the molten material from the first chamber to the second chamber through a discharge port communicating with the second chamber while moving through the first chamber; A heating element adjacent the second chamber to maintain the molten material in a semi-solid state within the second chamber; In the second chamber (a) retracting to generate a suction force to draw the molten material from the first chamber to the second chamber through the outlet and (b) advancing to eject the molten material into the mold A device for injecting a molten material into a mold, characterized in that it comprises a piston. 33. The apparatus of claim 32, wherein the first chamber includes a valve installed around an outer circumference of the hydraulic press to allow molten material to pass only in the direction toward the outlet. 33. The apparatus of claim 32, wherein the hydraulic press includes support pins arranged around the hydraulic press. 33. The apparatus of claim 32, further comprising a heating element provided along a longitudinal direction of the first chamber and the second chamber to adjust internal temperatures of the first chamber and the second chamber. 33. The apparatus of claim 32, wherein an open nozzle for injecting molten material into the mold is provided at one end of the second chamber. 37. The apparatus of claim 36, further comprising a nozzle barrier plate moving in a lift direction to connect the nozzle with a mold during closing and ejecting the nozzle. 38. The apparatus of claim 37, further comprising a heating element provided on or within the nozzle barrier plate. 33. The apparatus of claim 32, wherein the first chamber is located above the second chamber. 33. The apparatus of claim 32, wherein the first chamber is inclined at an angle between 30 degrees and 60 degrees with respect to the second chamber. 33. The apparatus of claim 32, wherein the second chamber includes a gas outlet to allow gas trapped between molten material and the piston to exit the second chamber. 43. The apparatus of claim 41 wherein the gas outlet includes a space between the piston and the wall of the second chamber. 33. The method of claim 32, A feeder connected to the first chamber by a supply port to supply the molten material to the first chamber; And And a heating element installed around an outer circumference of the feeder. 44. The apparatus of claim 43, comprising a third chamber in communication with the feeder. The method of claim 44, wherein the third chamber, A push arm for pushing the metal ingot into the third chamber; And And an inclined surface that assists the metal ingot to pass into the feeder. 45. An apparatus according to Claim 44 comprising an inert gas injection nozzle in said feeder or said third chamber. 45. The apparatus of claim 44, wherein said third chamber comprises a door installed in said three chamber. 45. The apparatus of claim 44, wherein the third chamber includes a movable cover plate that blocks or exposes the inlet of the feeder. 49. The apparatus of claim 48, wherein the movable cover plate includes a through hole corresponding to the inlet of the feeder. 44. The apparatus of claim 43, comprising a movable feed chamber for transferring a metal ingot to the feeder, wherein the movable feed chamber has a through hole for receiving the metal ingot. The method of claim 44, An elevator delivering a metal ingot; And And a conveyor disposed between the elevator and the third chamber to transfer the metal ingot from the elevator to the third chamber. The method of claim 51, wherein the elevator, Rotatable platform; A connector for causing the elevator to rotate around it; And And a lifting member for lifting the platform to rotate around the connector. 44. The apparatus of claim 43, wherein the feeder comprises a filter to prevent solid material from entering the first chamber. 54. The apparatus of claim 53, wherein the filter comprises a plurality of vertical bars or gratings installed within the feed port of the feeder. 33. The method of claim 32, wherein the piston includes an outer portion and an inner portion slidably fitted inside the outer portion, wherein the inner portion moves independently of the outer portion to prevent material from entering the mold through the injection nozzle. Device. 33. The apparatus of claim 32, wherein the oil press comprises an outer portion and an inner portion slidably fitted inside the outer portion, wherein the inner portion moves independently of the outer portion. Passing means for passing the molten material; Forcing means for driving the molten material from the passing means to an accumulating means for accumulating the molten material; Suction means for generating a suction force in the accumulation means to draw the molten material into the accumulation means; Heating means for maintaining the molten material in the second chamber in a semi-solid state; And injection means for injecting the molten material from the accumulation means into the mold. 58. An apparatus according to claim 57, comprising means for installing around said forcing means to allow said molten material to pass through only in a direction toward said accumulation means. 58. An apparatus according to claim 57, comprising heating means provided along said passing means and said accumulating means for heating said passing means and said accumulating means. 58. An apparatus according to claim 57, comprising means for closing said injection nozzle in said accumulating means and moving said injection nozzle in connection with a mold during injection. 58. An apparatus as in claim 57 comprising discharge means for removing gas from said accumulation means. 58. An apparatus according to claim 57, comprising melting means for melting solid material to form the molten material to be supplied to said passing means. 63. The apparatus according to claim 62, comprising filter means installed in the melting means to prevent the solid material from entering the passage means. 63. The apparatus according to claim 62, comprising holding means for holding said solid material before introducing it into said melting means for maintaining the inside of said melting means in an inert gas atmosphere. 65. An apparatus according to claim 64, comprising conveying means for conveying solid material to said holding means. 66. An apparatus according to claim 65, wherein said conveying means conveys said solid material to said retaining means when said door is opened in synchronization with a door of said retaining means. 19. The method of claim 18, wherein the inert gas atmosphere is maintained by a door installed in the third chamber and a vacuum pump connected to the third chamber. 19. The method of claim 18, wherein the inert gas atmosphere is maintained by a door installed in the third chamber and an inert gas screen disposed adjacent to the door. 42. The apparatus of claim 41 wherein the gas outlet includes a seal member surrounding the piston. 42. The apparatus of claim 41, wherein the gas outlet includes an opening in a wall of the second chamber that is coupled with a material that permeates gas and permeates liquid. 45. The apparatus of claim 44, wherein the third chamber comprises a door installed in the third chamber and a vacuum pump connected to the third chamber. 45. The apparatus of claim 44, wherein the third chamber comprises a conveyor belt connected to the third chamber. 45. The apparatus of claim 44, wherein the third chamber includes a heating element disposed outside the third chamber. 45. The apparatus of claim 44, wherein the third chamber comprises a door installed in the third chamber and an inert gas screen disposed adjacent to the door.

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